Impact crusher



E. B. MYERS IMPACT CRUSHER June 7, 1938.

2 Sheets-Sheet 1 Filed July 31, 1935 INVENTOR,

BY Elma/ 1 fi ing emf,

Jude/W36 W A ORNEY.

E. B. MYERS IMPACT GRUSHER June 7, 1938.

Fild July 31; 1935 2 Sheets-Sheet 2 4 INVENTOR,

Ebnum 5.111301 I BY a g a %0RNEYQ F I'V I Patented June 7, 1938 v UNITED STATES PATENT OFFICE IMPACT CRUSHER Elman B. Myers, Montreal, Quebec, Canada Application July 31, 1935, Serial No. 33,932

Claims. (Cl. 83-46) My present invention relates generally to the length whereby the particles fall by gravity and. crushing or disintegration of solid materials, and form a stream of increasing velocity. Then, withhas particular reference to improvements in out decreasing the cross sectional area of the crushers of the so-called impact type. stream, I introduce a gas traveling at a high 5 It is well known that solid materials of frangivelocity, which smoothly merges with the stream ble character, such as siliceous ores, talc, lime, of solid material. I have found that this can be pyrites, coal, and the like, if directed in the form done, without developing back pressures or otherof a high velocity stream against an anvil, are wise impeding or impairing the, smooth continu reduced in particle size. Various attempts have ous flow of the solid, by introducing the gas in:

heretofore been made to harness this phenomethe form of a tapering conical stream, the apex n non to the comminution or pulverization of maangle of the cone being less than 10 degrees and terials, but, because of various difliculties arising preferably about 6 degrees. In the illustrative from faulty design and a failure to understand embodiment of the invention the gas is introfully the underlying capabilities and shortcomduced at a midportion of the barrel hereinbefore ings of high velocity gas streams, no really pracmentioned. 15

tical apparatus has ever, to my knowledge, been Another feature of my invention lies in adedevised or employed. quately providing the maximum opportunity for In accordance with the present invention, I the solid material to acquire the higher velocihave successfully devised, constructed and operty of the gas. I have found that this may be ated an apparatus which is practical, effective in achieved by making the length of the barrel, 20 accomplishing its purposes, and eflicient, from the from gas inlet to muzzle, at least 14 times as great standpoints of cost and operation, volume of pmas the internal diameter. If the length is less, duction and rapidity and quality of resultant pulthe particles of solid material do not have an verization, in avariety of arts Where cumbersome adequate opportunity to accelerate to the ve- 5 and expensive ball-mills,-and the like, have been locity-of the gas stream; and if the length is too 5 regularly and tediously employed for effecting a great velocity decreases. much less adequate degree of comminution. My invention, furthermore, provides for ac- Since apparatus according to my invention is curate variation of the cross-sectional area of the admirably suited for the disintegration of freegas stream admitted into the barrel. This promilling ores, I have herein illustrated and devidesameans for efiective control of the quantity 30 scribed an installation designed primarily for this of gas employed, and this in turn enables the purpose. Nevertheless, it will be understood that .merger of gas and solids to be effected with maxithe features of my invention adapt themselves mum efficiency, depending upon the type, size with equal, and sometimes greater, facility and and specific weight of the material which is to be 5 advantage to many other industries and purposes. crushed. 1

- One of the features of my present invention lies One satisfactory structural mode of acco in the successful obviation of the difiiculty heretoplishing the foregoing objectives is to make the fore encountered in trying to effect an efficient material guiding and confining portions of the and adequate merger of a stream of solids with a barrel of two complementary sections of uniform 4O stream of high velocity gas. I have found that a internal diameter substantially throughout and 40 gas stream flowing at high speed manifests charhaving adjacent parallel surfaces which conform acteristics of a solid in that it resists entry thereto a downwardlyp rin Cone; the cto s ha into. Accordingly, to attempt to feed solids lat ing micrometric threaded portions which engage erally into such a stream is of no avail. On the with another portion of the barrel to provide a other hand, to direct a stream of gas laterally, or means for accurate relative axial adjustment of 5 even at most obliquities, into a mass' of solid, rethe sections. Such adjustment effects desired suits in building up undesirable back pressures variations in the width of the annular space or which prevent smooth, continuous, practical opgap between the sections, and a, high pressure gas,

eration. preferably but not necessarily, air, is introduced In accordance with my invention, I first impart into the barrel through said gap. 50 to the solids themselves a movement in the form One ofthe structural features of my invention of a stream, the particles being imbued with a lies in providing a replaceable lining or sleeve, of kinetic energy which resists deflection. This I special wear-resistant material at the muzzle of accomplish by feeding the material into the upper the barrel so as to withstand, for relatively long end of a vertical tubular barrel of adequate periods of time, the destructive abrasion of the 55 particles which emanate from the barrel at a high velocity.

Another feature of the invention lies in employing a. gas at a pressure which will develop the maximum theoretical velocity in the barrel. With air, a pressure of approximately 500 pounds per square inch has been employed, the theoretical velocity of the air stream generated being approximately 1150 feet per second. A pressure higher than this will not produce any material increase in velocity, whereas too little pressure will be inadequate to overcome the inertia of the solid particles.

I achieve the foregoing objectives, and such other objectives as may'hereinafterappear or be pointed out, in the manner illustratively exemplified in the accompanying drawings in which Figure 1 is a diagrammatic elevational view of an impact crusher embodying the features of mypresent invention; and

Figure 2 is an enlarged longitudinal cross-sectional view through the barrel itself.

Referring to Figure 1, the barrel of the present apparatus is designated generally by the reference numeral I 0, a funnel or the like ll being mounted at the upper end, and the lower or muzzle end l2'being arranged over an anvil l3. The anvil and the muzzle end of the barrel are enclosed within a chamber l4 having an outlet opening I5 at its upper end and having an outlet conduit [6 at the bottom. The conduit l6 leads into a second chamber ll which serves as a classifier. -It contains a bed-plate 18 arranged beneath the lower end of the conduit l6, and is provided with the outlet opening ill at its upper end and with the outlet chute 20 at the bottom.

Extending from the opening I5 is a conduit 2|, and extending from the outlet opening I9 is a similar conduit 22, the latter conduits leading into a tank 23, which may contain water. An

agitator 24 is preferably arranged within the tank and may be operated by a motor 25, or the like. At the upper end of the tank I provide an inlet pipe 26, and an air vent 21; and at the bottom of ,the tank a pipe 28 serves as an outlet.

Before describing the details of the present barrel I will point out that the solid material, in the'form of particles of free milling are for example approximately in size, is fed continuously into the hopper II, this feed being accomplished in any desirable or suitable manner. I have diagrammatically illustrated a traveling belt conveyer 29, adapted to deliver the material down a chute 30 into the funnel ll. However, any other suitable type of feeding mechanism may be employed and it is often preferable that the mechanism be of a character which gently agitates the particles as they are fed into the crushing apparatus. The stream of solid particles is discharged out of the muzzle l2 at a high velocity. The particles strike forcibly against the anvil I 3 and the anvil is preferably provided with the replaceable plate 3| which is of special wear-resistant material such as chromium-manganese-iron.

This impingement of the particles against the anvil causes disintegration of a portion thereof, to a powder of a fineness less than BOO-mesh. Approximately 60% of the powder mass has a size smaller than 5 microns, and some of the particles are even as small as one millimicron. These particles areobviously of air-float dimensions and most of them are withdrawn through the conduit 2|. A bailie ring 32 arranged within the chamber I4 serves to deflect the g r P rticles and causes them to travel downwardly through spaces 33 provided for this purpose in the anvil f 3.

The gas and particles which pass downwardly through the conduit I6 are again deflected by the plate l8 and additional fine particles are recovered' by passing outwardly through the conduit 22. The heavier particles are again deflected downwardly by the ring baffle 34, passing through openings 35 in the plate [8, and entering the chute 20. From here, these particles are led back to the hopper ll. w

The pulverized ore material entering the tank 23 through the conduits 2| and 22 is captured in suspended form by the water or other liquid in the tank and this suspension is continuously drawn off through the outlet 28, from which point it may be led to other apparatus where to be carried out in a practical, continuous, and

economical manner.

The barrel I0 is composed of two sections, the upper section 36 having a flange 31 secured to the funnel II, and having also a portion 38 provided with the micrometric screw threads 39. The internal diameter is uniform' throughout, except near the top where it enlarges somewhat to facilitate the admission of the solid particles. At the lower end of the section 36 the outer surface is downwardly-tapered, as shown at 40, thereby conforming this surface to a downwardlytapering cone having an apex angle no greater than 10 degrees and preferably 6 degrees.

The lower section 4| of the barrel is aligned with the upper section and has an internal diameter not less than that of the upper section. The upper portion of the section 4| has its inner surface 42 downwardly-tapered so that it forms a complementary parallel surface, relative to the tapered surface 40 of the upper section. This permits the two sections to define an annular conical passage-way 43 which serves for the admission of the high pressure gas in a downwardly-tapering conical stream.

At its lower end the section 4| is provided with a replaceable sleeve or lining 44 which is preferably of nickel-chromium-iron or boron carbide or similar wear-resistant material. This lining is held in place, in a replaceable manner, by means I of the ferrule 45. The opening 46 of the ferrule is purposely larger than the internal diameter of the barrel so that passage of the solid material, at high velocity, will exercise abrasive action if any against the lower corners 41 of the lining.

Carried by the lower section 4| is a gas-inlet manifold 48 which communicates with the upper end of the passageway 43. Gas at high pressure is admitted through the opening 49. The manifold 46 may, if desired, be formed integrally with the section 4|, but it is preferable to employ a threaded engagement, as indicated at 50, so

that the lower section 4| of the barrel may be completely replaceable, if desired. In effect, the manifold 48 forms a part of the lower section 4|, and is provided with micrometric screw threads which engage with the threads 39 hereinbefore mentioned. The reference numerals 5| and 52 designate lock nuts.

In accordance with my invention, the width of the gap 43 may be accurately controlled, and may be adjusted from a zero width to any selected size suitable for the gas employed, the pressure used, and the general purpose of the apparatus. This adjustment is effected by rotating the upper section 36, and by virtue of the micrometric threads 39, each complete rotation corresponds accurately to a definite alteration in the width of the gap 43. In this way varying amounts of gas may be introduced to meet different operating conditions.

Another feature of my invention, as hereinbefore mentioned, lies in the proportioning of parts so that the distance from the gas-inlet 43 to the muzzle end of the ,barrel is at least I4 times as great as the internal diameter. This affords opportunity for the high velocity gas to accelerate the solid particles up to effective velocities for disintegrating the particles on impact.

Because of the unconstricted' barrel and the acute angle of the conical passage 43, in combinationwith the adequate relative length of the barrel from gas-inlet to muzzle, the apparatus may be continuously employed in a highly eflicient manner. A continuous crushing of certain kinds of material at the rate of 10 tons per hour may, for example, be carried on by employing air at not over 500 pounds pressure and in a quantity of not over 600 cubic feet per minute. For such an output the length of the barrel, from gas-inlet to muzzle, was approximately 28 inches, and the internal diameter approximately 2 inches. The gas-inlet passageway 43 is of appropriate crosssectional area to provide the proper volume of air and the anvil I3 is arranged about 6 inches away from the muzzle. In using a barrel of the above dimensions and with the gas inlet angle as above set forth, the optimum position will be substantially that shown in Figure 2 of the drawings and the width of the inlet opening will be approximately .036 inch.

The foregoing relative dimensions are given merely for the purpose of explaining the general nature of the invention and it will be obvious that variations may be made to suit differing requirements. For example, another successful installation employs an internal diameter of about 1 inch, a. length of barrel, from gas-inlet to muzzle,

of approximately 18 inches, and an optimum gasinlet gap of approximately .026 inch. Such an arrangement of parts employs about 264 cubic feet of air per minute, at 500 pounds pressure, and crushes three tons of certain kinds of material per hour.

Various uses to which the present apparatus may be put will be obvious to those skilled in the art, but I wish to point out that, in addition to the crushing of ores, and the release of metallic values, such as copper, gold, silver, platinum, palladium, and the like, from quartz or similar materials, the apparatus is admirably suited for widelydiiferent purposes, notably the pulverization of coal.

Similarly, in the cement industry, the cement clinkers developed during the roasting process may be eficiently and inexpensively reduced to powder by the present apparatus, thereby obviating the necessity for the regular expensive and cumbersome employment of ball-mills, pebble-mills or the like.

Generally speaking, various advantages of the pressing machinery, is markedly less than that of conventional equipment of equivalent output capacity. I

The initial .cost of the present apparatus is much less than that of conventional mills; and the upkeep and maintenance costs are negligible compared to conventional costs.

Reduction in particle size of various materials may be effected in the dry state.

The space required by the illustrated apparatus is relatively small. -The chamber l4 and the chamber I! of Figure 1 occupy little over 10 feet in height and about 4 feet in width. The tank may be as little as 7 feet in diameter and 6 feet high. I

There are no moving parts, and the elements subject to wear may be easily replaced.

In general, it will be understood that changes in the details, herein described and illustrated for the purpose of explaining the nature of my invention, may be made by'those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims. It is, therefore, intended that these details be interpreted as illustrative, and not in a limiting sense.

Having thus described my invention, and illustrated its use, what I claim as new and desire to secure by Letters Patent is- 1. In an impact crusher, a barrel comprising separate coaxially arranged upper and lower sections, said upper section having an outer conical surface tapering at an angle of less than five degrees to its longitudinal axis and said lower section having an inner conical surface and a cylindrical bore, said inner surface being arranged opposite said outer conical surface and parallel thereto to form an annular conical passage opening into said lower section, and said cylindrical bore extending continuously from saidconical passage to the discharge end of said lower section, means for feeding material to be crushedthrough said upper section into said lower section, means for delivering gas under pressure into said cylindrical bore through said conical passage, and an anvil opposite said disbore extending continuously from said conical passage to the discharge end of said lower section, the length of said continuous cylindrical bore being at least fourteen times its diameter,- means for feeding material to be crushed through said upper section into said lower section, means for delivering gasunder pressure into said cylindrical bore through said conical passage, and an anvil opposite said discharge end of the lower section.

3. In an impact crusher, a barrel comprising separate coaxially arranged upper and lower sections, said upper section having a outer conical surface tapering at an angle of less than five degrees to its longitudinal axis and said lower section having an inner conical surface and a cylindrical bore, said inner surface being arranged opposite said outer conical surface and parallel Cal thereto to form an annular conical passage opening into said lower section, and said cylindrical bore extending continuously from said conicalpassage to the discharge end of said lower section, one of said sections being adjustable in relation to the other to vary the effective width of said passage, means for feeding material to be crushed through said upper section into said lower section, means for delivering gas under pressure into said cylindrical bore through said conical passage, and an anvil opposite said discharge end of the lower section.

4. In an impact crusher, a barrel comprising separate coaxially arranged upper and lower sections, said upper section having an outer conical surface tapering at an angle of less than five degrees to its longitudinal axis and said lower section having an inner conical surface and a cylindrical bore, said inner surface being arranged opposite said outer conical surface and parallel thereto to form an annular conical passage opening into said lower section, and said cylindrical bore extending continuously from said conical passage to the discharge end of said lower sec- 7 tion, the length of said continuous cylindrical bore being'at least fourteen times its diameter, one of said sections being adjustable in relation to the other to vary the efiective width of said passage, means for feeding material to be crushed through said upper section into said lower section, means for delivering gas under pressure into said cylindrical bore through said conical passage, and an anvil opposite said discharge end of thelower section.

5. Apparatus for crushing material by impact wherein said material is supplied to an'acceleration tube through a feed tube having its delivery end extending centrally into the inlet end of said acceleration tube and is accelerated therein by gas under pressure and discharged therefrom in an unimpeded stream against an anvil arranged opposite the discharge end of said acceleration tube at suflicient velocity to be crushed by impact with said anvil, characterized in that said delivery end of the feed tube has an outer surface disposed at an angle of less than five degrees to its longitudinal axis and said inlet end of the acceleration tube has an inner surface arranged in opposed spaced parallel relation to said outer surface and forms therewith in effect an injector nozzle passageway for supplying gas under pressure to said acceleration tube in an annular stream laterally enclosing the path of material delivered centrally into said acceleration tube throughsaid feed tube, and said acceleration tube has an acceleration and discharge end portion provided with a bore of a length at least fourteen times its diameter and of substantially undiminished cross-sectional area in the direction of movement of material therethrough, which crosssectional area is substantially the same as that of the bore of said delivery end of the feed tube, and with its discharge opening arranged opposite the anvil to discharge material freely from the delivery end of said feed tube into crushing impact with the anvil in an unimpeded stream of undiminished cross-sectional area from said delivery end of said feed tube to the impact surface of said anvil.

ELMAN B. MYERS. 

